Method of treating paper pulp



March 22, 1932. w. K.' TALB Oi ETHOD 0F TREATING PAPER ,PULF

Filed Oct. 8, 1925 2 Sheets-Sheet gvwe'nto'a William K. Tamar March 22, 1932. w. K. TALBOT METHOD OF TREATING PAPER PULP Filed Oct. 8. 1925 2 Sheets-Sheet 2 William- K. Talbo i' Patented Mar. 22, 1932 UNITED sures PATENT OFFICE WILLIAM R- TALBOT, OF SEATTLE, WASHINGTON, ASSIGNOR, BY ME ASSIGNHENTS,

'10 OSSIAN ANDERSON, F EVERETT, WASHINGTON EETHOD 0F TREATING PAPER PULP Application filed October 8, 1925. Serial No. 61,221.

My invention relates to methods of preparing paper pulp for shipment and the resulting product.

The object of my invention is to sotreat and prepare paper pulp as it is first made, that the contained water may be expelled therefrom in an expeditious and cheap manner, after which the dried product may be baled and shipped to the paper mills without having to pay freight upon contained water.

y invention consists of the method employed in securing this result and also the new and novel commercial product resulting therefrom.

In the accompanying drawings I have shown a form of apparatus which ma be used in carrying out my process, and ave filso illustrated the product resulting thererom.

Figure '1 shows in side elevation an apparatus which may be employed in handling the paper web as discharged from the pulp mill in the-preparation of my novel product resulting from the new process.

Figure 2 shows in side elevation a ress which may be employed in baling the ried pulp product.

Figure 3 is a horizontal or. plan view of a typical dry kiln apparatus which may be used in drying the product. In this fi re and also in Figure 1, the adjacent wall 0 the kiln has been omitted to more easily and clearly show the interior equipment. I Figure 4 shows a loose pile of the resulting product. j

Figure 5 shows a typical fragmentof the product, and,

Figure 6 shows a bale, in which shape the product is packaged for shipment.

In the manufacture of pulp in mills which are purely pulp mills, that is, where the pulp is shipped as pulp to other mills for manufacture mto paper, it is the common practice to fold the wet pulp sheets and package it into bales for shipment. As the pulp when baled contains approximately moisture, freight must be paid on as much water as pulp.

To avoid this difliculty I have devised a plan whereby the wet pulp as t comes from the pulp mill is put into such physical condition that it is practical to expel the moisture b passing it through a dry kiln, after which tli e dried pulp is baled for shipment. In this way the payment of freight u n a large Water content is avoided and a ige saving efiected. A practical manner of accomplishtration and description is deemed unneces-- l ositioned to receive and act upon the pulp sheet as it is discharged from the pulp mill, is a shredding apparatus which shreds the pulp sheet into small particles which are then deposited upon the conveyor of a dry kiln, in

passing through which dry kiln the moisture content of the shredded pulp is extracted.

The shredding apparatus illustrated consists ofa revolving frame or skeleton drum 2, this having a number of bars 20 provided Withprojecting spikes or' fingers 21, these i cooperating with a like stationary bar '22 having its spikes or fingers 23 spaced to al-- ternate in position with the spikes of the rotating drum. The bar 22 is pivoted and has an arm 24 which acts as a counterweight to hold the spike carrying her 22 in position. A stop 25, adjustable in position may be employed to hold the bar 22 in position and yet to permit swinging of the bar 22 down in case a mass of pulp should be fed to the shredder.- The size of the shredded fragments may to a certain extent be determined by the position of the bar 22,

these being larger as the bar 22 is swung downwards.

In Figure 5 I have shown a typical frag ment of the shredded product. They may be a series of individual fragments 30 jointed together as shown in full lines, or each fragment 30 may be severed from all others,

as along the dotted lines 31. The size of the 3 fragments may be varied as produced by the same apparatus by adjusting the position'of the stationary shredding bar 22. The more this bar is lowered the larger the fragments. If lowered sufliciently it may ermitpassage of the sheet without shredding.

The shredded fragments of the pulp sheet are de osited upon the endless conveyor 40 of a ry kiln 4. Means are provided for heating this kiln and for circulating air through the shredded pulp. Steam pipes 5 are provided for heating the air and circu lating fans 6. The conveyor 40 should be of openwork character, as of a wire screen character, so that air may pass freely through it. The shredded pulp piles up on this conveyor to quite a depth, as its movement is slow.

The wood pulp is fibrous in nature, and in high grade pulp the fibres are depended upon to lend strength to the finished aper stock. When the pulp is in a wet con ition, however, the fibres readily absorb moisture, thus almost wholly losing their tensile strength, and it is diflicult to efiect the shredding of the pulp without injuring the fibres thereof. It has been foundthat any rapidly rotating shredder of the beater type is wholly impracticable for use in shredding wood pulp, and I accordingly employ a shredder of the character described. The shredding devices are rotated at a relatively low speed, the spikes gently pulling small pieces of pulp from the body of the sheet and thereby substantially finely dividing it. The pulp is not finely shredded, but is divided into relatively small pieces which may be determined by adjusting the bar 22.

While I have described a particular type of dry kiln it is evident that any other type of dry kiln found to be suitable may be used.

When the dried shredded pulp is discharged from the dry kiln it is baled and is then ready'for storage or shipping. Any

suitable press may be used. The baling press, shown in Fi re 2, is a standard make, originally designe for baling hay.

A given amount of ulp when so dried weighs about half as muc as the same amount of pulp if baled in the customary way in its wet condition. In consequence the freight charges would be half as much for the same useful amount of product.

Experience has shown that it is impossible to dry the pul sheet in its original integral condltion wit out great complication and much time. By shredding the wet pulp sheet the particles are made small and these pile up loosely upon the conveyor so that air will circulate freely among them, thus facilitating their dryin When so pre ared it is possible to quic y dry them and y using standard dry kiln of simple construction.

The size of the individual shreddings may be made anything found feasible and desirable. This may be determined within certain limits by adjustment of the shredding members, and within wider limits by variation of construction, particularl as to spacing of the shredding pins and eir rate of rotation.

What I claim as m invention is:

1. The method 0 treating wood pulp which com rises separating wet pulp into a substantial y' loose divided condition by pulling relatively small pieces from the body of the ulp without injurin the fibres thereof, an drying the pulp w ile in such condition.

2. The method of treating wood pulp which comprises shredding wet pulp in a substantially loose divided condition bypulling relatively small pieces from the body of the 111 without injuring the fibres there of, an subjecting the pulp to the action of heated air to dry it.

Signed at Seattle, King County, Washington, this 26th da of Se tember, 1925.

W K. TALBOT.

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